Re: getting function name

["Thiago L." <fakedme@...>]

On 16/11/14 05:19 PM, jseb wrote:
> >    Take a look at package.loaded.  Not only does it contain a
> > reference to package, but it also contains a reference to _G.
> Ah yes, just saw that.
>
> And there were problem also in the searching loop: when found, the
> search continues and it ends with returning nil. Each returning
> call should test if there were some success previously.
>
> Correct version:
>
> function _get_fx_name(fx, t)
>    local ret = nil
>    for k,v in pairs(t) do
>      if fx == v then
>        print("found", k,v)
>        return k
>      end
>      if type(v) == "table" and k ~= "_G"  and k ~= "package" then
>        ret = _get_fx_name(fx, v)
>        if ret then goto exit end
>      end
>    end
> ::exit::
>    return ret
> end
>
> function get_fx_name(fx)
>    local name
>    name = _get_fx_name(fx, _ENV)
>    name = name or "unknown function"
>    return name
> end
>
>
> I know it's pretty not pretty, but that's the most i can do.
Use this: (just remember to modify get_fx_name with your name-picking 
algorithm)

Features: if _ENV has a t={} t[t]=t, it doesn't lock up.

local function scan(_table, _type, _callback, _userdata)
  local todo = {[_table] = true}
  local seen = {}
  local path = {}
  -- we can't use pairs() here because we modify todo
  while next(todo) do
    local t = next(todo)
    todo[t] = nil
    seen[t] = true
    for k, v in next, t do
      if type(v) == _type then
        _callback(t, k, v, _userdata)
      end
      if not seen[k] and type(k) == "table" then
        todo[k] = true
      end
      if not seen[v] and type(v) == "table" then
        todo[v] = true
      end
    end
  end
end

local function check_fx(t, k, v, userdata)
  if v == userdata.fx then
    table.insert(userdata.names, k)
  end
end

function get_fx_name(fx)
  local names = {}
  scan(_ENV, "function", check_fx, {names = names, fx = fx}) -- avoid 
making new closures
  -- pick a name from names
  return name or "unknown function"
end